If and when you decide to buy vintage vehicles and playsets, be on the look out for these accessories which more often than not, are missing from them. Even though the seller would say that "Oh, you can get that cheap on eBay or something", you probably would wind up paying more than if you got a complete one in the first place. Or if you have the luck and patience that I have, you could really get a bargain. I actually found two B-Wing guns in an eBay auction that I won for some scrappy parts inside the base of a Jabba's playset!
Millenium Falcon - training ball
Imperial Shuttle - ramp, windshield, side door
Y-Wing - top and front guns, long struts for back engines
B-Wing - wing guns, windshield
Sandcrawler - remote, ladder, droid elevator
Death Star playset - swing rope, dianoga monster
Jabba's palace - pipe, bowl, stand
AT-AT - chin guns
AT-ST - top gun, top cover
If I missed anything and I'm sure there are others, feel free to list them here. I almost forgot, those pesky battery covers are always missing from the electronic vehicles and playsets.